Mega Code Archive
Copy a file in reverse order
<![CDATA[
#include <stdio.h>
#include <stdlib.h>
int main(int argc, char *argv[])
{
long j;
FILE *in, *out;
char ch;
if(argc != 3) {
printf("Usage: revcopy <source> <destination>.\n");
exit(1);
}
if((in = fopen(argv[1], "rb")) == NULL) {
printf("Cannot open input file.\n");
exit(1);
}
if((out = fopen(argv[2], "wb"))==NULL) {
printf("Cannot open output file.\n");
exit(1);
}
/* find end of source file */
fseek(in, 0L, SEEK_END);
j = ftell(in);
/* copy file in reverse order */
j = j-1; /* back up past end-of-file mark */
while(j >= 0L) {
fseek(in, j, SEEK_SET);
ch = fgetc(in);
fputc(ch, out);
j--;
}
fclose(in);
fclose(out);
return 0;
}
]]>